Weak Pinning and Long-Range Anticorrelated Motion of Phase Boundaries in Driven Diffusive Systems.

We show that domain walls separating coexisting extremal current phases in driven diffusive systems exhibit complex stochastic dynamics with a subdiffusive temporal growth of position fluctuations due to long-range anticorrelated current fluctuations and a weak pinning at long times. This weak pinning manifests itself in a saturated width of the domain wall position fluctuations that increases sublinearly with the system size. As a function of time t and system size L, the width w(t,L) has a scaling behavior w(t,L)=L^{3/4}f(t/L^{9/4}), with f(u) constant for u≫1 and f(u)∼u^{1/3} for u≪1. An Orstein-Uhlenbeck process with long-range anticorrelated noise is shown to capture this scaling behavior. The exponent 9/4 is a new dynamical exponent for relaxation processes in driven diffusive systems.

Biofiltration of H(2)S with reclaimed water as a nutrient/moisture source at loading rates from 10 to 300 g H(2)S m(-3) h(-1).

A biofilter was evaluated with two different media under field conditions using reclaimed water as a nutrient source. Evaluation with a single medium demonstrated that H(2)S could be efficiently removed at volumetric loading rates of up to 200 g H(2)S m(-3) h(-1). After an extended period of high loading rates, the performance began to deteriorate at loading rates greater than 150 g H(2)S m(-3) h(-1) possibly due to nutrient limitations. The reclaimed water served as a nutrient source even though the primary form of nitrogen was nitrate. The reclaimed water successfully supplied nutrients at the majority of loading rates observed in the study and this was verified by stoichiometric calculations. The biofilter was converted to a dual media filter and consistent performance was also observed with the dual media filter at loading rates up to 150 g H(2)S m(-3) h(-1). The biofilter was successfully operated at loading rates higher than previously reported under field conditions. The use of nitrate in reclaimed water as a nitrogen source was successful and demonstrated the potential to eliminate the need for a separate nutrient source at a water reclamation plant.